The refrigeration technique is widely used in industry, military, medical and daily life. At present, most refrigeration equipments use traditional compression refrigeration techniques. However, such refrigeration methods have problems such as low refrigerating efficiency and difficulty in miniaturization of equipment, and refrigerants used in compression refrigeration may cause serious damage to the environment. Thus, there is urgent need to develop a novel refrigeration method.
Electrocaloric refrigeration is a novel refrigeration method. An external electric field is applied to the electrocaloric material to stimulate phase transition in the electrocaloric material, and thus refrigeration is achieved by the heat absorption effect caused by the phase transition. Electrocaloric refrigeration belongs to solid-state refrigeration and does not need refrigerants that are harmful to the environment. Furthermore, electrocaloric refrigeration features high refrigerating efficiency, low energy consumption, easy miniaturization and so on, and thus attracts extensive attention in the field of refrigeration technique. In recent years, the ferroelectric polymer exhibits a strong electrocaloric effect, is easy-to-form and lightweight, and thus becomes one of the important materials for electrocaloric refrigeration devices and techniques.
However, the ferroelectric polymer has a low electrocaloric strength (that is, a stronger electrocaloric effect need to be stimulated by a higher electric field), which brings great difficulty to the design of electrocaloric refrigeration device and reduces the stability and reliability of the device. Meanwhile, the ferroelectric polymer has a low thermal conductivity, namely, heat conduction in the electrocaloric material is difficult, which seriously restricts the refrigerating power density of the electrocaloric device. Therefore, it is of great significance to develop an electrocaloric material with a strong electrocaloric effect and a good thermal conductivity under a low electric field.